Supercritical CO2 extraction of pungent components from immature and mature Japanese pepper has been conducted in order to study the effect of extraction condition on the yield of extract and composition of pungent components in the extract. Extraction was carried out in semi-continuous extractor at pressure of 9-45 MPa, temperature of 40-80 degrees C and CO2 flow rate of 1-3 mL/min. Composition of pungent compounds in the extract was analyzed by GC-MS, while sanshool compounds was qualitatively analyzed by HPLC-DAD. Extraction condition significantly affected the yield of extract and the composition of pungent components in the extract. In general, extraction yield of mature Japanese pepper was higher than immature one. Extraction condition can be tuned to obtain higher content of the target pungent components. The extract was mainly contained hydroxy-alpha-sanshool as the most abundant of sanshool compounds followed by alpha- and delta-sanshool. As comparison with the conventional methods, supercritical CO2 extraction effectively extracted the pungent components of Japanese pepper in high yield. (C) 2009 Elsevier B.V. All rights reserved.